1. Field of the Invention
The present invention relates to a photosensitive composition capable of changing its properties by undergoing a reaction upon irradiation with actinic rays or radiation, a compound for use in the photosensitive composition, and a pattern forming method using the photosensitive composition. More specifically, the present invention relates to a photosensitive composition for use in the production process of a semiconductor such as IC, in the production of a circuit substrate of liquid crystal, thermal head or the like, in other photofabrication processes or in the lithographic printing plate or acid-curable composition, and also relates to a compound for use in the photosensitive composition and a pattern forming method using the photosensitive composition.
2. Description of the Related Art
The chemical amplification resist composition is a pattern forming material capable of forming a pattern on a substrate by producing an acid in the exposed area upon irradiation with radiation such as far ultraviolet light and through a reaction using this acid as the catalyst, changing the solubility in a developer between the area irradiated with actinic radiation and the non-irradiated area.
In the case of using a KrF excimer laser as the exposure light source, a resin having small absorption in the region of 248 nm and having a basic skeleton of poly(hydroxystyrene) is predominantly used as the main component, and this is an excellent system capable of forming a good pattern with high sensitivity and high resolution as compared with the conventional naphthoquinonediazide/novolak resin system.
In the case of using a light source of emitting light at a shorter wavelength, for example, in using an ArF excimer laser (193 nm) as the light source, a satisfactory pattern cannot be formed even by the above-described chemical amplification system because the compound having an aromatic group substantially has large absorption in the region of 193 nm.
In order to solve this problem, a resist containing a resin having an alicyclic hydrocarbon structure with high transparency has been developed for use with an ArF excimer laser. As for the alicyclic hydrocarbon structure, a norbornene or adamantane skeleton showing high transparency and high dry etching resistance is used as described in JP-A-2002-131897 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”)), JP-A-2003-149812, JP-T-11-501909 (the term (the term “JP-T” as used herein means a “published Japanese translation of a PCT patent application”), JP-A-2002-268223, JP-A-2003-246786 and JP-A-9-73173. However, the alicyclic structure generally has low polarity, and the reactivity for deprotection in the resin is greatly decreased as compared with that in poly(hydroxystyrene). Therefore, an acid having high acidity is necessary for the image formation and a specific fluoro-organic sulfonic acid is used, for example, in JP-A-2002-131897 and JP-A-2003-149812. Also, a composition containing an acid generator comprising an imide anion capable of generating a high-acidity imide upon irradiation with actinic rays or radiation is described in JP-T-11-501909, JP-A-2002-268223 and JP-A-2003-246786. Furthermore, in JP-A-6-242606, JP-A-11-160861, U.S. Patent Application 2004/0087690A1, a specific organic sulfonic acid is used.
In addition, as for the chemical amplification-type resist composition, a resist composition containing a specific amide compound is described in JP-A-5-181263, WO01-004706, pamphlet and JP-A-11-327145.
However, many points still remain unsatisfied, and improvement is demanded with respect to the pattern profile, line edge roughness and defocus latitude depended on line pitch.